I like to go through Derpibooru adding missing pony, earth pony/pegasus/unicorn, mare, and stallion tages to images of characters.
However, take Sandbar and Pistachio. I naturally tend to put “stallion” on their images, since they aren’t truely full colts like Rumble. But I’ve seen the “teenager” tag on them too sometimes.
Can “teenager” and “stallion” co-exist? I think both can be true, it doesn’t have to be an either or thing. I see those two guys as stallions, still. Just younger stallions.